For the first time doctors have been given the go-ahead to deploy experimental drugs for all patients in an Ebola outbreak, according to the WHO.

Its latest report on the outbreak in the Democratic Republic of the Congo (DRC) puts the number of deaths at 28 out of 55 cases recorded since the epidemic began in early April.

The DRC has approved five experimental treatments, including two drugs used to treat the only baby to survive Ebola in the West Africa epidemic.

“We don't know if the epidemic is over — one case can spark a new cluster”

Séverine Caluwaerts

The drugs are experimental because they have not yet completed the large-scale trials normally required but officials believe approval is warranted in an emergency, as long as patients give consent and results are monitored.

The approval by the Congolese government is being followed up by ongoing negotiations with the WHO and the medical charity Doctors without Borders (MSF-Medicines Sans Frontiers). The aim is to fine-tune the details on which of these drugs are to be used as a first-line of defence, according to Séverine Caluwaerts, a gynaecologist with the charity.

“MSF specifically wants to focus on Zmapp as first line, and [on a drug called] GS-5734,” she told SciDev.Net.

The two drugs were among three experimental therapies used successfully by MSF to save Nubia — the only baby known to have survived being born with Ebola — in Guinea towards the end of the West Africa epidemic in 2015.

Zmapp, a cocktail of monoclonal antibodies, initially improved Nubia's condition. But it wasn’t enough to clear the virus until she was given GS-5734, also known as Remdesivir. “Because the Zmapp was not enough to clear her virus, we sort of believe in the GS compound but this is more belief, no science, since the sample size is too small,” explains Caluwaerts.

“There’s a solid argument in favour of Zmapp but not Remdesivir until further evidence is developed,” says Daniel Kelly, from the School of Medicine at the University of California, San Francisco in the United States, who has worked on the Ebola response in Sierra Leone over the years.

Kelly believes the drugs can be useful for special cases, but WHO’s guidance for “aggressive supportive care” — such as IV fluids for severely dehydrated people — should still be what doctors turn to first.

Nubia is only the second person worldwide to be given Remdesivir. The first is Scottish nurse Pauline Cafferkey who caught the deadly virus in Sierra Leone.

Nubia was born just a few days after her mother was admitted to a treatment centre run by MSF. She left the centre 33 days later, just two weeks after doctors administered the drug, weighing 3100 grams and showing no signs of illness. She is now 2.5 years old and thriving.

The Ebola virus is particularly deadly for foetuses and newborns, and until Nubia, the longest a baby had survived during the West Africa epidemic was two days.

Caluwaerts calls Nubia a “miracle” and a “game-changer”: she is the first documented survivor of Ebola passed on during pregnancy. Before her, everyone thought no baby could survive if born to a mother who caught the virus while pregnant, she said at MSF’s Scientific Days conference last month (May 17-18).

At the conference Caluwaerts presented results from the largest study yet on Ebola-positive pregnant women, which she said holds lessons for doctors now working in the DRC.

Evidence from past cases suggested that nine in 10 pregnant women would die of Ebola, but there were still questions to answer, she explained — for example whether pregnancy worsens a woman’s diagnosis, or if amniotic fluid is infectious.

Analysis of data for 77 pregnant women from nine MSF treatment centres in Guinea, Liberia and Sierra Leone showed that pregnant women were as likely to survive the disease as uninfected women of reproductive age — but they had a higher chance of survival if they caught the virus in the early stages of pregnancy.

In the study, which is due to be published in a peer-reviewed journal, Caluwaerts and her colleagues also report that amniotic fluid tests “strongly” positive for the virus up to 32 days after a pregnant woman recovers from the disease.

This has implications for the safety of health workers treating women who either deliver babies or miscarry. She recommends that staff working in the DRC make sure pregnancy testing is standard at admission for all women of childbearing age, and that all pregnant patients who test positive for Ebola should deliver inside a treatment centre but in a private maternity space.

Mortality in MSF’s treatment centres in the DRC stands at 20-30 per cent, much lower than in previous epidemics, and there are signs the epidemic is waning: no new cases have been reported since May 17, according to the WHO. But the charity remains cautious. “We don't know if the epidemic is over — one case can spark a new cluster,” says Caluwaerts.